Conventional vehicular steering systems have an articulated mechanical linkage connecting the input device (e.g., steering wheel) to the steering actuator (e.g., steerable road wheels, rudder, etc.). Even with power assist, the operator of such a mechanically linked vehicle can generally feel the forces acting against the actuator through the input device.
Commercial and recreational vehicles, such as those used in construction, agriculture and marine environments, generally require the input of steering commands through a steering wheel to accomplish directional control. For many of these vehicles, the actuating device or controlled surface that changes the steering direction is not mechanically connected to the steering wheel. These systems are generally referred to as xe2x80x9csteer-by-wirexe2x80x9d.
For high performance speedboats and construction equipment employing xe2x80x9csteer-by-wirexe2x80x9d systems, for example, a phase lag may occur when the operator applies a fast steering input at the steering wheel but the directional control actuator has difficulty keeping in correspondence with the operator""s steering command. For some large construction equipment, for example, the directional control actuator may draw additional power from the vehicle""s energy supply source in order to keep up with the steering input command, but this additional power drain may reduce the power available to other vehicular systems.
In an exemplary embodiment, a steer-by-wire system includes a steering wheel; a steering wheel sensor coupled to the steering wheel for sensing the position of the steering wheel and producing a signal indicative of the position of the steering wheel; a controller in signal communication with the steering wheel sensor for receiving the signal indicative of the position of the steering wheel from the steering wheel sensor and producing a signal indicative of a desired steering wheel feedback torque; and a tactile feedback device in signal communication with the controller for receiving the signal indicative of the desired steering wheel feedback torque and providing a corresponding torque to the steering wheel.